International aid for cyclone victims in Burma was deliberately blocked by the military regime, the first independent report into the disaster has found.

The junta's wilful disregard for the welfare of the 3.4 million survivors of cyclone Nargis – which struck the Irrawaddy delta last May, killing 140,000 people – and a host of other abuses detailed by the research may amount to crimes against humanity under international law.

The teams of Burmese volunteers and experts from a US university that conducted the research urged the UN security council to refer the regime to the international criminal court.

The report After the Storm: Voices from the Delta outlined how the Burmese authorities failed to provide adequate food, shelter or water for the survivors.

But the military regime, which was at the time preparing for a national referendum on its plans to hold elections in 2010, insisted it could cope with the disaster despite its scale and shunned most international relief for weeks.

Researchers from Johns Hopkins University in the US and Burmese volunteers from the Emergency Assistance Team (Eat-Burma) spent months interviewing survivors and relief workers about the cyclone's aftermath.

Their study found that the Burmese army obstructed private cyclone relief efforts even among its own concerned citizens, setting up checkpoints and arresting some of those trying to provide help.

Supplies of overseas relief materials that were eventually allowed into Burma were confiscated by the military and sold in markets, the packaging easily identifiable.

"I went to some of the markets run by the military and authorities and saw supplies that had been donated being sold there," a former Burmese soldier who fled to Mae Sot across the border in Thailand told the researchers. "The materials were supposed to go to the victims. I could recognise them in the market."

The researchers were repeatedly told that surviving men, women and even children were used as forced labour on reconstruction projects for the military.

"[The army] did not help us, they threatened us," said one survivor from the town of Labutta. "Everyone in the village was required to work for five days, morning and evening without compensation. Children were required to work too. A boy got injured on his leg and got a fever. After two or three days he was taken to [Rangoon], but after a few days he died."

Professor Chris Beyrer, director of the centre for public health and human rights at Johns Hopkins, said the Burmese regime's response to the disaster violated humanitarian relief norms and legal frameworks for relief efforts.

The systematic abuses may amount to crimes against humanity under international law through the creation of conditions where basic survival needs of people are not met, "intentionally causing great suffering, or serious injury to body or to mental or physical health", he said.